When to start sleep training
Not before 4 months. Between 4 and 6 months is the usual start, and the research was done with babies of 6 months and older. Here is what each source says.
What age can you start sleep training?
| Source | What it says |
|---|---|
| Cleveland Clinic (2025) | Babies are often ready to begin sleep training at about 4 months. Some are ready slightly earlier, others closer to 6 months. |
| Dr. Richard Ferber's book (1985 and 2006) | Five or six months. |
| Sleep Foundation (2025) | Sleep training, including the Ferber method, can start once a child is 6 months old. |
| The published trials | All enrolled babies of 6 months and older. |
| American Academy of Pediatrics | No policy sets a minimum age. |
No medical body sets an age. If you are not sure your baby is ready, check with your pediatrician first.
Why not before 4 months?
Young babies have short sleep cycles and cannot make it through the night without eating. Their sleep has no regular pattern yet, which is also why the American Academy of Sleep Medicine gives no sleep recommendation under 4 months.
A 2013 review of the research found that sleep training in the first 6 months had not been shown to reduce crying, to prevent later sleep problems or to protect against postnatal depression.
What you can do before 4 months
- Feed your baby whenever they are hungry, day and night.
- Keep night feeds dark and quiet, so nights feel different from days.
- Do the same short routine before every night sleep.
- Once a day, lay your baby down drowsy but awake. If they do not settle, help them and try again tomorrow.
- Follow the safe sleep basics: on the back, on a firm, flat surface, with nothing else in the crib or bassinet.
Starting at 4 or 5 months
This is the age where the sources differ. Our plans use a method where you stay in the room at 4 and 5 months and add timed checks and the say-goodnight method from 6 months, because that is where the research starts.
Many babies of this age still need a feed at night. Sleep training does not have to mean dropping feeds, and you should not cut a night feed at this age without your pediatrician.
From 6 months
From 6 months the main approaches are staying in the room and moving away over two weeks, timed checks (the Ferber method), and saying goodnight and not going back in (cry it out). A 2006 review for the American Academy of Sleep Medicine found that 49 of 52 studies reported better sleep, and found too little evidence to recommend one method over another.
Night weaning is safe when a baby is healthy and at a good weight, and you can sleep train and night wean at the same time (Cleveland Clinic). Ask your pediatrician before you cut a feed.
Is it ever too late?
No. The same methods are used with toddlers. A child in a bed they can leave needs a version with check-ins, and a calm walk back to bed every time they get up.
Born early?
For a baby born more than a few weeks early, pediatricians count development from the due date for the first 2 years. No source says how that applies to sleep training, so ask your pediatrician which age to use.
Get a plan that fits your baby's age
Answer nine quick questions. Under 4 months the plan uses routines and gentle settling only. From 4 months it adds a 14 night method matched to how you feel about crying.
Related guides
Sources
- Cleveland Clinic. When and How To Sleep Train Your Baby. January 2025.
- Ferber R. Solve Your Child's Sleep Problems. First edition 1985; revised edition 2006.
- Sleep Foundation. Ferber Method. Updated July 2025.
- Douglas PS, Hill PS. Journal of Developmental and Behavioral Pediatrics, 2013 (systematic review, first 6 months).
- Mindell JA, et al. Behavioral treatment of bedtime problems and night wakings in infants and young children. Sleep, 2006 (review for the American Academy of Sleep Medicine).
- Paruthi S, et al. Recommended Amount of Sleep for Pediatric Populations: A Consensus Statement of the American Academy of Sleep Medicine. Journal of Clinical Sleep Medicine, 2016.
General information for parents, not medical advice. Independent, not affiliated with the American Academy of Pediatrics or any medical body. Talk to your pediatrician about your baby's health.